About conditions of spatial collapse in an infinite system of Bose particles

TL;DR

This paper demonstrates that spatial collapse in an infinite Bose gas is not solely determined by the scattering length, challenging previous predictions based on the Gross-Pitaevskii equation.

Contribution

It introduces a variational principle approach showing collapse conditions differ from those predicted by the Gross-Pitaevskii equation.

Findings

Collapse is not solely dependent on scattering length.

Gross-Pitaevskii equation predictions are challenged.

Spatial collapse conditions are more complex than previously thought.

Abstract

Using the variational principle, we show that the condition of spatial collapse in a Bose gas is not determined by the value of the scattering length of the interaction potential between particles contrary to the result following from the Gross--Pitaevskii equation, where the collapse should take place at a negative scattering length.